Heat penetration and quality analysis of retort processed vegetables for home meal replacement foods

Heat penetration characteristics of different vegetable products were investigated during retort processing. A custom-developed variable temperature retort-sterilizer allowed us to test the following target retort-temperatures; 120, 130, 140, and 150 °C, combined with the following holding times: 1, 3, 5, 7 min. Radish showed the highest heating rate (9.56 ± 0.21 °C/min) among the tested vegetables, including radish, carrot, and potato. Textural qualities of retort-processed vegetables showed a close correlation with thermal dose. Hardness of potato was 3.07 ± 0.07 N after retort processing at 120 °C for 7 min, with a thermal dose of 127 ± 7 k °C s. Better hardness (3.72 ± 0.06 N) was obtained after retort processing at 150 °C for 3 min, with a thermal dose of 122 ± 6 k °C s. The data reported herein indicate that retort temperature should be appropriately controlled for different vegetable products based on their specific heat-penetration characteristics.